Question

. Male drosophila typically have a higher potential reproductive output than females because a. The more females fertilized, the higher the male's fitness b. Females are limited by the resources that they have to use to produce eggs c. Males do not provide any parental care d. All of the above e. None of the above 2. The handicap theory of mate choice in sexual selection says that : a. Male display genes spread and female choice genes only spread because they become linked to male display genes. b. Males will advertise in a limited way because males in low condition are not physically able to signal at a higher level. c. Males will advertise at a level that matches their condition because if they signal at a higher level the mortality cost outweighs the mating choice benefit. d. Females will make mating decisions based on the signal that males give but this will not be related to male condition or male quality. 3. In a study of parental care by burying beetles, the following data were obtained: Female care only Female and male both care Weight of larvae 3.7 g 2.4 g Probability of intruder killing young 0.45 0.12 The change in larval weight does not significantly effect future survival of the larvae. These data suggest that: a. Males do more harm than good because the weight of larvae is less in clutches with male care. b. Males increase their indirect fitness by helping the female. c. Male parental care has a positive effect on the number of surviving young. d. The number of surviving young is the same with and without male assistance. 4. Parental care in fish is more likely to be provided by only the male: a. when males already guard territories. b. when males defend groups of females. c. in species with internal fertilization. d. in species that live in cold environments.

Answer 1

1d. All the above

In males, as mating frequency increases relative fitness also increases proportionally. Providing parental care is also costly, such that as care increases, parental death rate increases and parental reproductive rate decreases. Finally in insects such as Drosophila males do not provide any parental care. So in all reproductive potential output in male Drosophila is higher than that of females.

2d. Females will make mating decisions based on the signals that males give but this will not be related to male quality or male condition.

Zahavi’s ‘handicap principle’ proposes that females prefer males with handicaps (mating characters that reduce survival chances) because handicaps are indicators of heritable viability. This means that If only males with high-quality genes can survive possessing a handicap, a female who mates preferentially with handicapped males will only mate with males with good genes, like peacock`s tail.

4a. When males already guard territories